Should Short-Course Neoadjuvant Radiation Therapy Be Applied for Low-Lying Rectal Cancer? A Systematic Review and Meta-Analysis of the Randomized Trials

Radiation Therapy for Rectal Cancer: An ASTRO Clinical Practice Guideline Focused Update

PURPOSE

With the results of several recently published clinical trials, this guideline focused update provides evidence-based recommendations for the indications and dose-fractionation regimens for neoadjuvant radiation therapy (RT), optimal sequencing of RT and systemic therapy in the context of total neoadjuvant therapy (TNT), and considerations for selective omission of RT and surgery for rectal cancer.

METHODS

The American Society for Radiation Oncology convened a multidisciplinary task force to update 3 key questions that focused on the role of RT for patients with operable rectal cancer. The key questions addressed (1) indications for neoadjuvant RT, (2) selection of neoadjuvant regimens, and (3) indications for consideration of a nonoperative management (NOM) or local excision approach after definitive/preoperative chemoradiation. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for quality of evidence grading and strength of recommendation.

RESULTS

For patients with stage II-III rectal cancer, neoadjuvant RT was strongly recommended; however, among patients deemed at lower risk of locoregional recurrence, consideration of omission of neoadjuvant RT was conditionally recommended in favor of neoadjuvant chemotherapy with a favorable treatment response or upfront surgery. For patients with T3-T4 and node-positive rectal cancer undergoing neoadjuvant RT, a TNT approach was strongly recommended. Among patients with higher risk of locoregional recurrence, TNT with chemotherapy before or after long-course chemoradiation was strongly recommended, whereas TNT with short-course RT followed by chemotherapy was conditionally recommended. For patients with rectal cancer for whom NOM is a priority, concurrent chemoradiation followed by consolidation chemotherapy was strongly recommended. Selection of RT dose-fractionation regimen, sequencing of therapies, and consideration of NOM should be determined by multidisciplinary consensus and based on disease extent, disease location, patient preferences, and quality of life considerations.

CONCLUSIONS

The task force proposed recommendations to inform best clinical practices on the use of RT for rectal cancer with strong emphasis on multidisciplinary care. Future studies should focus on further addressing optimal treatment regimens to allow for more personalized recommendations based on individual risk stratification and patient priorities regarding quality of life.

Management of Locally Advanced Rectal Cancer: ASCO Guideline

ASCO Guidelines provide recommendations with comprehensive review and analyses of the relevant literature for each recommendation, following the guideline development process as outlined in the ASCO Guidelines Methodology Manual. ASCO Guidelines follow the ASCO Conflict of Interest Policy for Clinical Practice Guidelines.Clinical Practice Guidelines and other guidance ("Guidance") provided by ASCO is not a comprehensive or definitive guide to treatment options. It is intended for voluntary use by providers and should be used in conjunction with independent professional judgment. Guidance may not be applicable to all patients, interventions, diseases or stages of diseases. Guidance is based on review and analysis of relevant literature, and is not intended as a statement of the standard of care. ASCO does not endorse third-party drugs, devices, services, or therapies and assumes no responsibility for any harm arising from or related to the use of this information. See complete disclaimer in Appendix 1 and 2 (online only) for more.PURPOSETo provide evidence-based guidance for clinicians who treat patients with locally advanced rectal cancer.METHODSA systematic review of the literature published from 2013 to 2023 was conducted to identify relevant systematic reviews, phase II and III randomized controlled trials (RCTs), and observational studies where applicable.RESULTSTwelve RCTs, two systematic reviews, and one nonrandomized study met the inclusion criteria for this systematic review. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.RECOMMENDATIONSFollowing assessment with magnetic resonance imaging, for patients with microsatellite stable or proficient mismatch repair locally advanced rectal cancer, total neoadjuvant therapy (TNT; ie chemoradiation [CRT] and chemotherapy) should be offered as initial treatment for patients with tumors located in the lower rectum and/or patients who are at higher risk for local and/or distant metastases. Patients without higher-risk factors may discuss chemotherapy with selective CRT depending on extent of response, TNT, or neoadjuvant long-course CRT or short-course radiation. For patients who are candidates for TNT, the preferred timing for chemotherapy is after radiation, and neoadjuvant long-course CRT is preferred over short-course radiation therapy (RT), however short-course RT may also be a viable treatment option depending on circumstances. Nonoperative management may be discussed as an alternative to total mesorectal excision for patients who have a clinical complete response to neoadjuvant therapy. For patients whose tumors are microsatellite instability-high or mismatch repair deficient, immunotherapy is recommended.Additional information is available at http://www.asco.org/gastrointestinal-cancer-guidelines.

Quality of life and late toxicity after short-course radiotherapy followed by chemotherapy or chemoradiotherapy for locally advanced rectal cancer - The RAPIDO trial

BACKGROUND AND PURPOSE

The RAPIDO trial demonstrated a decrease in disease-related treatment failure (DrTF) and an increase in pathological complete responses (pCR) in locally advanced rectal cancer (LARC) patients receiving total neoadjuvant treatment (TNT) compared to conventional chemoradiotherapy. This study examines health-related quality of life (HRQL), bowel function, and late toxicity in patients in the trial.

MATERIALS AND METHODS

Patients were randomized between short-course radiotherapy followed by pre-operative chemotherapy (EXP), or chemoradiotherapy and optional post-operative chemotherapy (STD). The STD group was divided into patients who did (STD+) and did not (STD-) receive post-operative chemotherapy. Three years after surgery patients received HRQL (EORTC QLQ-C30, QLQ-CR29 and QLQ-CIPN20) and LARS questionnaires. Patients who experienced a DrTF event before the toxicity assessments (6, 12, 24, or 36 months) were excluded from analyses.

RESULTS

Of 574 eligible patients, 495 questionnaires were returned (86%) and 453 analyzed (79% completed within time limits). No significant differences were observed between the groups regarding QLQ-C30, QLQ-CR29 or LARS scores. Sensory-related symptoms occurred significantly more often in the EXP group compared to all STD patients, but not compared to STD+ patients. Any toxicity of any grade and grade ≥ 3 toxicity was comparable between the EXP and STD groups at all time-points. Neurotoxicity grade 1-2 occurred significantly more often in the EXP and STD+ group at all time-points compared to the STD- group.

CONCLUSION

The results demonstrate that TNT for LARC, yielding improved DrTF and pCRs, does not compromise HRQL, bowel functional or results in more grade ≥3 toxicity compared to standard chemoradiotherapy at three years after surgery in DrTF-free patients.

Shared Decision-Making and Short-Course Radiotherapy for Operable Rectal Adenocarcinoma: A Patient's Right to Choose

BACKGROUND

As new treatment options for colorectal cancer (CRC) emerge, physicians and WOC nurses must be prepared to assist patients to choose care that meets their needs and preferences. A patient with T2N0M0 rectal adenocarcinoma was offered the US current standard of practice; he was not offered alternative treatment options. This case study emphasizes the need to ensure patients are offered all reasonable options for treatment. Shared decision-making is a process that helps patients actively participate in their heath choices rather than exclusively relying on the judgment of a health care provider.

CASE

Mr J was a 70-year-old man with operable CRC who sought care at a health care facility in his community. He was offered a single option, based on standard of care for this tumor stage: long-course neoadjuvant chemoradiotherapy followed by surgery and additional chemotherapy. After seeking a second opinion at a cancer care center in another state, Mr J chose to undergo a viable alternative treatment option (short-course radiotherapy, followed by surgery, with chemotherapy contingent on his nodal status post-surgery). No nodal involvement was found post- surgery (T2N0M0) enabling him to avoid postoperative chemotherapy.

CONCLUSIONS

This case illustrates the need for all health care providers and carers to regularly engage in shared decision-making when choosing among treatment options. In this case, short-course radiotherapy offered Mr J a shorter duration of treatment and avoided the risk for adverse side effects associated with chemotherapy, resulting in improved health-related quality of life. Initial omission to disclose all treatment options to Mr J may have reflected the preferences of the surgeon, institutional financial pressures, or discomfort with shared decision-making, but it failed to provide him with full range of options, given his diagnosis and tumor stage. All members of the patient's care team, including the WOC nurse, play a pivotal role in ensuring transparency in medical care, including advocating for shared decision-making where patients are made aware of all viable treatments, followed by supporting the patient as they reach a decision.

Neoadjuvant Modified Short-Course Radiotherapy Followed by Delayed Surgery for Locally Advanced Rectal Cancer

This study aimed to assess the clinical outcomes and predictive factors of neoadjuvant modified short-course radiotherapy (mSC-RT) for locally advanced rectal cancer (LARC). Data from 97 patients undergoing mSC-RT followed by radical surgery for LARC were retrospectively analyzed. A 2.5 Gy dose twice daily up to a total dose of 25 Gy in 10 fractions was administered through mSC-RT, and this was delivered with oral chemotherapy in 95 (97.9%) patients. Radical surgery was performed 6 (range, 3-13) weeks after mSC-RT. The median follow-up among surviving patients was 43 (8-86) months. All patients completed neoadjuvant radiotherapy with no acute toxicity grade ≥ 3. Three- and five-year local control rates were 96.3% and 96.3%, respectively. Three- and five-year overall survival (OS) rates were 92.7% and 79.8%, respectively. Univariate analyses revealed that poor OS was associated with no concurrent administration of capecitabine, C-reactive-protein-to-albumin ratio ≥ 0.053, carcinoembryonic antigen ≥ 3.4 ng/mL, and neutrophil-to-lymphocyte ratio (NLR) ≥ 1.83 (P = 0.045, 0.001, 0.041, and 0.001, respectively). Multivariate analyses indicated that NLR ≥ 1.83 was independently associated with poor OS (p = 0.018). mSC-RT followed by delayed surgery for LARC was deemed feasible and resulted in good clinical outcomes, whereas poor OS was associated with high NLR.